package com.semlab.server.enrichment.util;

public class LevenshteinDistance {
    private static int minimum(int a, int b, int c) {
            return Math.min(Math.min(a, b), c);
    }

    public static int computeLevenshteinDistance(CharSequence str1,
                    CharSequence str2) {
            int[][] distance = new int[str1.length() + 1][str2.length() + 1];

            for (int i = 0; i <= str1.length(); i++)
                    distance[i][0] = i;
            for (int j = 0; j <= str2.length(); j++)
                    distance[0][j] = j;

            for (int i = 1; i <= str1.length(); i++)
                    for (int j = 1; j <= str2.length(); j++)
                            distance[i][j] = minimum(
                                            distance[i - 1][j] + 1,
                                            distance[i][j - 1] + 1,
                                            distance[i - 1][j - 1]
                                                            + ((str1.charAt(i - 1) == str2.charAt(j - 1)) ? 0
                                                                            : 1));

            return distance[str1.length()][str2.length()];
    }
}
